Classified as Least Concern (LC) on the IUCN Red List and listed on Appendix II of CITES (4).

Considered sacred by the ancient Egyptians (2), the hamadryas baboon is distinguished from other baboons by the male’s long, silver-grey shoulder cape, and the pink or red rather than black face and rump (3) (5). Like all baboons, the hamadryas baboon is a large monkey with a dog-like face, pronounced brow ridges, relatively long limbs with short digits, rather coarse fur, and a relatively short tail, which in this species has a tufted tip. The male is considerably larger than the female, and has a heavy cape, bushy cheeks, and large canine teeth (2) (3) (5) (6). While the male hamadryas baboon develops a silvery-grey coat, the juvenile and female are brown, with dark brown skin on the face and rump (2) (5). The female hamadryas baboon develops colourful and pronounced sexual swellings during oestrus (3) (5) (6), and the skin over the rump becomes bright red during pregnancy (3). This species sometimes hybridises with the olive baboon (Papio anubis) where the ranges of the two overlap, in a small area of northern Ethiopia (3) (6) (7).

The hamadryas baboon occurs in northeastern Africa, where it is principally found in Ethiopia, but also ranges into eastern Sudan, Eritrea, Djibouti and northern Somalia. It also occurs in the Arabian Peninsula, in Saudi Arabia and Yemen (1) (2) (7), where it is the only native non-human primate (8). The range of this species once extended into Egypt, where it is now extinct (1).

This species inhabits arid subdesert, steppe, hilly areas, escarpments, alpine meadows and mountains (1) (3) (5), at elevations of up to 3,300 metres in Ethiopia (1). It is never found far from water, and may migrate seasonally in some parts of its range, moving into mountain areas during the wet season (1).

Like all baboons, the hamadryas baboon is primarily terrestrial, but will sleep in trees or on cliffs at night (2) (6). An opportunistic feeder, it will take a wide variety of foods, including grass, fruit, roots and tubers, seeds, leaves, buds and insects (1) (2) (3) (6). Baboons may also hunt small mammals, including hares and young gazelles (3) (6). The female hamadryas baboon usually gives birth to a single young, after a gestation period of 170 to 173 days (2). Breeding may take place at any time of year, but births typically peak between May and July or November and December in Ethiopia (2) (5), and each female usually only gives birth once every 15 to 24 months (3) (9). The newborn hamadryas baboon has black fur and pink skin (3), and is suckled for up to 15 months (2). Lifespan in captivity has been recorded at 37 years (2).

The social system of the hamadryas baboon is intriguing in its complexity and its unique levels of organisation. Each adult male controls a small group of females (a harem) and their young, and remains bonded with the same females over several years, aggressively ‘herding’ any that wander, and retaining exclusive mating rights over the group. The females will often compete to groom and stay close to the male, and it is the male who dictates the group’s movements. Solitary males may sometimes follow the group. Males from a number of these family units often cooperate and interact, and may be closely related, forming associations known as ‘clans’. At the next level of organisation, several one-male units regularly interact in ‘bands’ of about 30 to 90 individuals, and a number of bands often share the same sleeping site, forming a ‘troop’ of up to several hundred individuals (2) (3) (6) (10) (11). Young males adopt a number of strategies to obtain females, including luring or abducting a juvenile female from a group, and guarding her until she is old enough to breed (3) (5) (11). While male hamadryas baboons typically remain in the natal clan for life, young females may transfer between clans or even bands (3) (9) (11).

The hamadryas baboon is not currently thought to face any major threats, and may even be increasing in some areas (1). The species is generally tolerated and even sometimes actively fed by people, and often lives around cities and garbage dumps, sometimes reaching pest proportions in settled areas, and showing little fear of humans (2). Although not commonly hunted for food, the hamadryas baboon is sometimes shot for skins, trapped for medical research, or killed for pest control, particularly where it raids crops (1) (7). Locally, the hamadryas baboon may be at risk from habitat loss, due to overgrazing, agricultural expansion, and irrigation projects, which can also increase conflict with humans (1) (2) (7).

International trade in the hamadryas baboon should be carefully monitored under its listing on Appendix II of the Convention on International Trade in Endangered Species (CITES) (4), and the species also occurs in a few protected areas (1) (7), including the Simien Mountains National Park in Ethiopia, a World Heritage Site (12). However, despite being the focus of much conservation activity, this park has suffered problems with overgrazing, development and deforestation, and is in one of the most densely populated agricultural areas in Africa (12). The hamadryas baboon is listed as ‘vermin’ by the African Convention on the Conservation of Nature and Natural Resources (1) (13). No specific conservation measures are in place for the species (7), but a number of research projects are underway into its behaviour and ecology (10).

Recent studies have suggested that the population of hamadryas baboons in Arabia colonised the peninsula much longer ago than previously thought, and shows a considerable amount of genetic variation compared to the African population. In light of this, it has been suggested that the conservation status of the population in the Arabian Peninsula be raised, and that a management programme be put in place to ensure its long-term survival there, while seeking to minimise conflict with humans (8).